FabFilter User Forum
Building a Dynamic Tremolo in Volcano3?
Hi! I’ve been trying to build a dynamic tremolo in Volcano, but am stuck.
What I want is something like this guitar pedal: youtu.be/cW5owKRWd6U?si=9kcZoQZjp3zspR_o
What I have:
* XLFO controlling the level.
* Envelope Generator on the input (guitar), adjusting the XLFO’s frequency.
That sorta works, but what I’d like is:
Instead of the envelope generator, I want the XLFO’s frequency to adjust based on the input level. Is that possible within Volcano? Is something like that possible in Volcano? (I’m on an iPad, if that makes a difference.)
Thanks!
whistlercowboyjazz — Mar 31, 2025
Hi!
As far as I can tell this is what you are doing now. You can modulate the XLFO frequency with an envelope follower or generator to adjust the modulation frequency on the incoming signal.
Hi Ralph! Thanks for responding. I may be confused about how envelope followers work. Perhaps you can set me on the right track.
The issue I'm having with the envelope generator is the concept of the threshold. Correct me if I'm wrong, but my understanding is:
* Once the input level crosses the threshold, the envelope is generated. ie. it triggers the change to the XLFO.
* This envelope only triggers when the threshold is crossed.
* If the input level crosses the threshold, but then remains above the threshold, the envelope generator is sorta "done"?
What would feel more natural would be no threshold at all:
Input level goes up -> XLFO frequency goes up.
Input level goes down -> XLFO frequency goes down.
I've tried to understand how envelope _followers_ work, as I feel like maybe the solution is in there, but I haven't been able to find any ELI5-level tutorials about how an envelope follower works. The only YT video I could find that included it showed it used to change the attack on the input, but I couldn't figure out how to connect it to the XLFO.
Sorry if my questions don't even make sense. I have a feeling I'm off about some of my assumptions and it's causing me to ask nonsensical questions :)
You can use the envelope follower the same way you'd use the envelope generator. The only difference is that the envelope follower takes the envelope as the input signal as its base, where the generator generates a whole new envelope. You can use both to modulate the XLFO rate, but the EF will probably give you a more natural sustain compared to the EG. As the input signal drops the release will set in, decreasing the XLFO rate.
Huh, thanks! I'm not sure what I was doing wrong before, but I couldn't seem to connect the envelope follower (via the little dot) to anything else. I think that threw me off, but I just tried again and can. Will continue my explorations. Thanks a ton!
Also thanks for the tip that I could use both the EG and EF together. Will experiment with that too!